Wire the Kiro provider into BaseExecutor baseUrls fallback so a request
advances across the three CodeWhisperer surfaces (runtime kiro.dev,
codewhisperer, q) on 429 and network/5xx errors.
- providers.js: add baseUrls[] (newest endpoint first); keep baseUrl as default
- kiro.js: replace the hand-rolled single-endpoint loop with super.execute()
delegation plus EventStream to SSE transform on success
Note: the three hosts are alternate DNS surfaces of one regional service. AWS
throttles per authenticated identity (token plus profileArn), not per hostname,
so this is edge-level failover, not extra 429 quota.
Co-authored-by: thienpv <pvtcwd@gmail.com>
Co-authored-by: Cursor <cursoragent@cursor.com>
